The invention concerns a stent for the bracing and/or for the holding open of a hollow organ with a tubular self-expanding network comprising filaments that, in a collapsed state of the lumen is axially stretched and, in a expanded state of the lumen is axially foreshortened and which is constructed from at least two bands.
A stent of this type is described in the european patent application EP 94 106 490.9.
With patients having an increased surgical risk, the transluminal utilization of stents for the bracing or for the permanent opening of stenoses or of other sources of narrowing of the lumen of hollow organs is particularly advantageous. Invasive surgery and diagnostic measures can be supplemented with the assistance of interventional radiology and of various visual diagnostic methods or, in an advantageous case, rendered superfluous. Through the transluminal implantation of stents it is possible to permanently hold open the lumen of a vessel or of a hollow organ.
The stent described in the above-cited european patent application is comprised of two bands which have rectangular cross sections and which are attached to each other at crossing points of the stent. The known stent exhibits, in a collapsed state, a smaller diameter than a self-expanding stent made from round filaments and the rectangularly cross-sectioned stent can be manufactured from a reduced number of bands. The connection of the bands at the crossing points is achieved by completely jacketing the bands at the crossing points. It is possible for the bands to move in a hinged fashion with respect to each other within the jacketing layer. Depending on the material chosen for the jacketing, an increased restoring force out of the collapsed state of the stent into the expanded state can be effected. The bands mutually seat via their metallic surfaces at the crossing points and the crossing bands are completely jacketed in plastic so that a secure hinge is formed at the crossing point.
It is the underlying purpose of the invention to further improve a self-expanding stent of the above-mentioned kind such that as evenly distributed a seating of the bands as possible on the inner wall of a hollow organ is guaranteed with the restoring forces of the stent being extendable via the crossing points, and a safe and stable application of the stents is achieved by means of an improved linkage at the crossing points.